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20 Feb 2019

Photobiomodulation Lecture 2015 (Low Level Light Therapy)

Watch as Dr Lew Lim and leading scientists from Harvard Medical School and Boston University School of Medicine, share their insights about the positive effects of low level light therapy (photobiomodulation) on the body and brain at the cellular level.


Speaker 1:  life for me when before he started treatment was very very stressful it was unbelievable, he used to wander he would go through he would go through cupboards, he would oh it was just any would have temper tantrums and it was very very. Very difficult it was very stressful. Yeah that’s it yeah it’s better now. right yeah it’s better yeah much better, right?


Speaker 2: much better

Speaker 1: I’d kind of tear up now because it was so awful before.

Speaker 2: I guess yeah

Speaker 3: It seems with dimension you don’t see. I guess you see everything right but you don’t feel everything

Speaker 4: this study that were involved in is a feasibility study so it’s relatively small but it is a randomized control study

Speaker 3: with the treatment, I feel a lot better. Nothing’s dull anymore I can look around and nothing’s dull

Speaker 1:  it was a complete change he became calm, he stopped wandering. He was able to sleep at night and he stopped searching for everything.

Speaker 4:  essentially what we’re doing is evaluating the patient’s at three points baseline, where are they before they start treatment halfway through treatment at six weeks and that at completion of treatment of 12 weeks

Speaker 1: and then she told me that I had to give it up

Lew Lim:  hello everyone my name is Lew Lim,  I am truly looking forward to taking you on this journey of understanding healing with light. At the end of this journey, you will take away three things,  an understanding of the healing power of light, how it works and how you can use its power to heal yourself and others. As an example, I will show you its potential to address Alzheimer’s disease.

Now let’s get into this lecture, today this healing process with light is called photobiomodulation. Photo means light bio means the biological system and modulation is associated with change and alterations. it is progressively replacing the long-standing label of low-level light therapy and is part of this exciting field of photomedicine. In this lecture, I will often mention red and near-infrared light which are parts of the light spectrum that are most relevant to photobiomodulation. It’s because it is this range that have been found to cause ourselves to go into a healing process.

Narrator: photo by modulation helps your body to use its own ability to heal more effectively. Have you noticed your body can heal on its own it can overcome the common cold and repair wounds we will show you the way to enhance this capability with light but first step let’s look briefly at how photobiomodulation began.

Margaret Naeser: actually it was an accidental finding that Andre Mester discovered, that applying red photons or red light to wounds that were not healing well would make them heal better. nd he was actually trying to cause skin cancer and he had two groups of rats and he shaved all the hair off the backs of each group of rats,  and hmm he was going to have an experimental group where he’s going to shine these red just red light this red laser and he’s going to see if he can cause skin cancer. And then he has the control group and he’s not going to do anything to them well surprise surprise all the hair grew back twice as fast on the back that had received the red laser light. And he said oh my goodness this is a beneficial effect it’s never going to cause skin cancer it’s going to heal wounds. And so that was a beginning of an accidental finding and from then on people were off studying why is the red light effective to help the cells.

Narrator: any important experiments in a photo medicine are now carried out in respected research institutions in North America including Harvard Medical School Boston University Stanford MIT Texas in the University of Toronto as well as top institutions around the world including in Russia and China or a lot of discoveries are being made. Today you’ll find light therapy devices and chiropractic clinics for pain reduction in dental offices, in hospitals for cancer treatment, in veterinarian hospitals from any application and in homes where they are used for treating winter depression and other conditions.

Narrator: The power of where will photobiomodulation therapy lies and what it can offer you effectiveness no major side effects, affordability, ease of use and most of all light energy that is natural.

Lew Lim: in this lecture, I will be explaining the ability of your body to seek out where healing is needed within his biosystem when light energy is properly introduced. additionally, I’ll show you a new and promising solution for delivering light energy to key areas within the brain to improve recovery from neurological disease and cognitive performance.

Narrator:  like powers life it is that fundamental understanding how our bodies react to light enables us to utilize that knowledge for healing evolutionary biology tells us that life on earth began nearly four billion years ago as a few connected molecules responded to light from the Sun. This response included the production of nucleic acids the precursors of the DNA that carries genetic codes for every form of life over billions of years these molecules continue to harness photon or quanta of light energy to proliferate into cells and form bigger and more complex organisms.

Lew Lim: the study explained the signaling that takes place when the photons are delivered to the cells resulting in a healing process, more of this later. Now, now at this point, you might be asking yourself why have you not heard of this form of therapy if it has such promise? Good question!  there are no big marketing dollars for the medicine because simply there is no company the size of the pharmaceutical giants however, interest grows because the science is plausible the evidence is growing and most of all people who have benefited are spreading the word. one of those people is dr. Michael Hampton of Harvard Medical School dr. Hamlin is one of the most esteemed thought leaders in the world of photomedicine and probably has more published books and peer-reviewed articles with his name than anyone else in the world in this field.

Michael Hamblin, PD: I can easily tell you what excited my interest in Ischl e invited by modulation I was doing a lot of research and photodynamic therapy so they use  ight plus photosensitizing guys to kill cancer cells. You want to kill bacteria you want to kill undesirable tissue and when you do these experiments you have to have a light alone control, okay so it’s usually red light because that excites the photosensitizers, so you put red light alone and you find that’s doing exactly the opposite of photodynamic therapy PDT so it’s not killing things it’s actually stimulating them. So once you do these control experiments a few times you sort of can’t ignore it I mean a lot of people in the PDT field assume that light alone does nothing right it’s like negative control but it actually does do something and then once you see that you can study it so that’s how I got into it.

Michael Hamblin, PD: Once you see that shining low levels of red or near-infrared light onto tissue has a positive effect which is not what intuitively would expect you would expect it have no effect right it’s just like once you see it does have a positive effect then it scientifically it becomes very intriguing to see what’s going on.

Lew Lim: let’s now delve deeper into the mechanism of photobiomodulation to understand how and why it works from the cellular level right up to the systemic levels. let’s begin with the mitochondria

Narrator: mitochondria are the energy factories that exist within almost every cell they are the key to photobiomodulation. mitochondria have a substance called the cytochrome days that can absorb red and near-infrared light and convert the energy into a form of biological energy called adenosine triphosphate or ATP. what is ATP essentially it acts as a signaling molecule that leads to healing and tissue repair. The process also generates a mild level oxidant, reactive oxygen species abbreviated as ro s which is another signaling molecule to start the action of transcribing genetic factors that lead to tissue repair. This is where physical healing can be accelerated when you introduce red and near-infrared light.

Narrator:  there is another important molecule in the picture nitric oxide, nitric oxide can be a major factor that contributes to cellular dysfunction if it sits in the cell it clogs the respiratory chain. So what is the respiratory chain?  the respiratory chain is the process that leads to generating ATP it is the core of the mitochondria low-level red and near-infrared light actually freeze the nitric oxide back into the body and restores the function of the respiratory chain, then it takes on an important wide-ranging role of improving nerve function and improving blood circulation by relaxing the blood vessel wall.

Lew Lim: The cellular mechanisms are complex we can summarize the key players during photobiomodulation.

  1. Cytochrome oxidase the substance that absorbs light
  2. ATP for cellular energy and signaling
  3. ROS  mild oxidant that signals for cellular repair
  4. nitric oxide which when released by the photon improve cellular functions it has a healthy impact on the central nervous system  it will also help to relax the blood vessels and improve blood circulation

Narrator: cells respond to the photons when they are functioning below par or are not in homeostasis or in a balanced state

Lew Lim: therefore light energy is only selectively used when needed there is a built-in check and balance to ensure that there is no over stimulation, that is provided that the light energy is kept low that is why for many years the process is called low-level light therapy.

Narrator: when the cells respond collectively the effect becomes system the body goes through a negative feedback loop which means that whenever gets negative feedback in the system like something is not working properly. The response by correcting it to meet its set point of optimum health. This loop continues until the problem is corrected as far as possible.

Lew Lim: what is going on photobiomodulation has been experimentally and practically shown to make a healing difference in the immune system the vascular system endocrine system where the hormones are controlled and of course the brain. When we speak of internal systemic healing of the body intranasal like therapy of which I’m very familiar with is one of the most promising, It is the foundation of what I do as co-inventor. But how did it evolve?


Narrator: during the 1980s Russian scientists developed a technique that involved injecting low-level laser light to the blood circulatory system through the vein. it was successful as a holistic treatment to help with metabolic, activity blood circulation, systemic pain, inflammation immune system, and several other indications. It became very popular in centers were set up throughout Russia and various parts of the world to offer this modality. Patients still travel to these centers for treatment. The challenge with this technology was that using a needle to inject the light is invasive and only specifically trained technicians are qualified to do the procedure.

Lew Lim:  But could that be a way we achieve this with a non-invasive solution the answer is actually on our face. since the objective is to irradiate the blood with low-intensity red laser we can achieve the same effect by irradiating the system by the nasal passage or where there is a rich supply of capillaries near the surface of the membrane.

Narrator: there were more blood capillaries per square centimeter just underneath the nasal membrane than almost anywhere in the body. As an added bonus when you place a light source inside the nasal cavity there is little barrier between it and the brain, not only does this remove the need to use a needle this allows the technology to be downsized into something portable allowing the user to use it anywhere and at any time. these discoveries make it a potentially wearable technology for general wellness.

Lew Lim: given all of this how impactful is it when you introduce light energy into the circulatory system this way,  have a look at these clips.

Narrator:  these images are from blood samples taken before and directly after a single 25-minute treatment of intranasal blood irradiation. we found that 92 percent of cases respond this way. Persistent stickiness of the blood is found to be associated with elevated risk for a cardiovascular event like a heart attack as well as diabetes.

Lew Lim: but what happens in the brain? Brain cells and neurons are another form of cells now have the basis to make that statement about the potential a photobiomodulation of the brain.  Let’s now take a look at a difficult condition like Alzheimer’s disease.

Narrator:  Alzheimer’s disease we lose cognitive functions because the disease significantly shrinks your brain over time. There is no consensus on how Alzheimer’s disease is developed, the most widely followed is the amyloid hypothesis which proposes that beta amyloid t is the primary causative agent for Alzheimer’s disease. These plaques are toxic to brain tissues.  many critics believe that it is merely a biomarker that is created by the disease. Other hypotheses include those that relate to the deficiency of the neurotransmitter acetylcholine, the tau protein abnormalities which lead to the formation of neurofibrillary tangles, oxidative stress on the mitochondria, intake of metals such as aluminum and copper herpes simplex virus environmental pollution myelin sheath breakdown and a few more. For someone who has already developed the disease the best that existing pharmaceuticals can offer is to temporarily restore cognitive function  usually for about six months to a year. this is not a reversal. there is still nothing on the horizon for the estimated 40 million people around the world who’ve been diagnosed as having Alzheimer’s disease or alternative forms of dementia.

Lew Lim: now what if we just forget about being fixated with trying to attack the biomarkers and symptoms and just trust the body’s intelligent response when we’re happy by directing near-infrared light to the neurons. So let’s actually look at the signs related to photobiomodulation specifically relating to the brain and Alzheimer’s disease. I have already explained that cells are able to harness light energy for survival and propagation, and neurons are just another form of complete with the necessary structures that enable them to do the same.

Narrator: impaired neurons respond positively to near-infrared light. there are several published studies that demonstrate that damaged neurons restore their structures after irradiation with red and near-infrared light, not just on cells and experiments but also on laboratory rats with Alzheimer’s disease. neurons damaged by oxidative stress which is the basis of one of the hypothesized causes of Alzheimer’s disease has also been found to recover in a similar fashion after radiation with near-infrared light. Now if you subscribe to the amyloid hypothesis this therapy does indeed reduce amyloid beta protein as well as the precursors it mitigates the damage of the disease and improves cognitive functions.

Lew Lim: there have been a range of studies carried out with the writing light to the brain in the form of transcranial photobiomodulation.

Narrator: researchers at the University of California San Francisco just discovered that stem cells become neurons in the presence of persistent light energy. This is the basis to hypothesize that if stem cells are present in the brain the regular presence of light energy in the brain could result in new neurons.

Lew Lim: at the forefront of research on photobiomodulation on human brains is DR.. Margaret Nazar

Dr. Margaret Nazar: I’m a research professor of neurology at Boston University School of Medicine and I’m located here at the Boston VA Medical Center where I conduct research with light-emitting diodes applied to the head and into the nose to treat the brain to improve cognition and thinking. And veterans who have suffered traumatic brain injury or have PTSD or a special group of veterans who served in Kuwait in 1990-91 and they have developed what is known as Gulf War illness. I actually got into photobiomodulation work through my studies in acupuncture. I’ve worked with stroke patients who have language problems probably for 43 years now and I have note I had noticed that my stroke patients would have paralysis and it would be rather level in their recovery and I had read papers and sort of learned about this in San Francisco, I used to live in California that you could apply acupuncture to treat paralysis and stroke patients.  In 1984 a doctor from Shanghai China came to MIT here in Boston area and gave a three-day class on laser acupuncture. laser acupuncture what could that be well it meant shining a red light a laser light on the acupuncture points no needles just shining laser light on the acupuncture points so in 1985 I went to Shanghai China I studied for two months at the hua Shan Eun the shanghai number-one medical college, and i learned how to do laser acupuncture it’s very simple. you just put the red beam laser light it’s painless you don’t burn the skin it’s non-invasive painless, completely and you just put on the acupuncture points and you eventually after all maybe four weeks you see a change in their paralysis and it’s very helpful it helps about 66 percent of stroke patients. I brought that information back to the Boston VA Medical Center here instead of treating stroke patients with paralysis. I did learn about light-emitting diodes applied to the head. I learned about that from Anita saltmarsh in Toronto Canada and I also learned a lot about it from Michael R Hamlin PhD cell biologist at Mass General Hospital. l what is the treatment protocol with the light emitting diodes for a traumatic brain injury patient or PTSD patient is going to be very different from that for a stroke patient who had a stroke just on one side of the head and it’s eye that’s on the left it’s going to cause language problems. You really just want to put those LEDs where the brain damage is now with traumatic brain injury that is often caused by accelerated twisting the head goes forward and is twisted so you get damaged on both sides of the brain, so that’s fine to treat both sides of the brain with traumatic brain injury or and then often those are the patients who have PTSD also so that’s why you would want to treat both sides of the head with those patients and we get very good results

Lew Lim: let’s now continue with our quest to improve neurological outcomes. we have seen that near-infrared light can heal impaired neurons and this usually takes some time depending on the subjects conditioning and the nature of his disease. do we know for sure that the near-infrared light can get the neurons of the human brain to immediately start responding? The answer is, YES!  I was surprised and how active the brain is in trying to restore normative brain condition in just one session. stay with me for a while

Narrator:  this cue EEG reading is one of the healthy twenty-two-year-old in the pre treatment recording, you’ll notice some fairly mild abnormalities in different brain waves. Simply, abnormalities are seen as represented in any color other than pure green in the top two roads. after 25 minute illumination of the brain with near-infrared light there are heavy restorative activities throughout the brain our as represented in red and blue connectivity lines in the bottom three rooms, as a result, we see more normative brain waves represented by more errors restored to green after the treatment.  It appears that that restoration continues beyond the treatment.

Lew Lim: experiments at healing the brain with light are not that old the technique traditionally involves the writing light to the brain through the skull called transcranial light therapy. Published studies go back to about 10 years and they reported successful experiments and lab mice with stroke. since then studies have covered human subjects with traumatic brain injury and stroke some of them documented by dr. Margaret Nazar and the research collaborators using transcranial clusters of red and near-infrared LEDs.

Dr. Margaret Nazar:  the first patient big car hit her from behind in her smaller car the driver of that car was going about 55 miles an hour and was focused on a green light a block away, but failed to see the red light where she was stopped. this woman was highly educated she tottered University in New York had had basically a whiplash traumatic brain injury she had been a professor teaching web design. she had to resign all her professional work for six years. The longest she could work on a computer was 20 minutes, she had been through all sorts of cognitive rehabilitation therapy programs.  so she had her first treatment when we treat traumatic brain injury we apply the light emitting diode cluster heads and we place them all over the head we do six at a time about ten minutes per placement and there are two sets of placements in order to cover the whole head. And we treat every 48 hours during the week so outpatient treatments they come in its Monday Wednesday Friday and we do that for six weeks and then we test. She went to her computer and she could work on her computer for 40 minutes now that was twice which she could have done for the preceding six years then she kept going back once a week and after eight weeks that would be two months, she could work on her computer for two hours.  so she was so happy because she’s basically described as I got my brain back.

another traumatic brain injury case who we’ve been able to help quite a bit was a gentleman who through a work-related accident was actually pulled into a blast furnace. got a lot of facial trauma and broken bones in the face and then for two years after this accident he had a lot of problems thinking and problems with cognition problems with memory, so we treated him with our treatment program transcranial treatment program and he was treated Monday Wednesday Friday for six weeks and then we tested him at the sixth week.  there was again significant improvement in executive function and in verbal memory but the most striking finding for him was he was so grateful that after three weeks of the led treatments to his head he no longer had recurring nightmares of the accident, where he had been pulled into the blast furnace and that had been going on for two years.

Lew Lim:  taking this further I wanted to see how we can deal with the great challenge of Alzheimer’s disease. if we can successfully deal with this surely this will go a long way to support the efficacy of photobiomodulation for tough neurological conditions in general. perhaps we can help all those people who have developed Alzheimer’s disease.

Narrator: we approach this challenge with some experience on our side. A growing number of people are reporting significant improvements with the existing near-infrared intranasal device but it has not been as consistent as we would like. How can we improve the outcomes we combined intranasal with transcranial?

Lew  Lim: when we wanted to make this available to many people we were faced with two challenges.

Narrator: the first was to get light through the skull in an efficient manner. The second was to provide an effective and affordable solution that people with Alzheimer’s disease could use on a daily basis. Our first challenge is that of getting light into the brain. we knew from past published research that certain near-infrared wavelengths are particularly good not only because they travel deeper into the tissues they are not lost by being absorbed by blood and water before they reach the brain. This was later confirmed by the work of dr. Juanita Anders of the uniformed services University and her research collaborators. Furthermore, they found that a certain range of near-infrared light was also effective with nerve tissues. The wavelength was identified as around 810 NM the same wavelength we had been using successfully with her intranasal device.

Lew Lim: we now know that this is the wavelength that we should use for the transcranial portion. What else can we do to propose an efficient design. Brain imaging work has revealed that Alzheimer’s disease lesions are closely related to the hubs of the default mode network in the brain.

Narrator: The default mode Network kicks in when we are resting and not performing a task your brain never actually rests.  Many neurologic conditions are associated with a dysfunctional default mode network so it could be very important that our default mode network is healthy. Alzheimer’s disease is just one of these conditions the others include Parkinson’s disease multiple sclerosis autism schizophrenia depression chronic pain and others.

Lew Lim: so how do we achieve a healthy default mode network? we know that the network is interconnected with the hubs which are like busy railway junction. In fact, the lesions associated with Alzheimer’s disease are also found in this hubs the other information we know is that our brain cells heal we’re near infrared lights are directed into them. Hence,  the rational solution is to direct the infrared light energy to the hubs of the default mode Network.

Narrator: we are now putting this intranasal transcranial combination product to the test in a properly designed controlled study. The independent clinician is Anita salt marsh one of our early research collaborators with dr. nazar we’ve heard from earlier.

Anita Saltmarche: a study that were involved in is a feasibility study so it’s relatively small but it is a randomized controlled study.

Speaker 1: life for me when before he started a treatment, was very very stressful. It was unbelievable he used a 1, so what happened is in 2001 my husband had a serious head-on car crash and they thought he was dead and so the ambulance took their time to get there. He started to lose his memory then about five years ago he got diagnosed with dementia or Alzheimer’s.  

Speaker 2: seems with dementia huh clearly I guess you see everything right but they don’t feel everything right.

Speaker 1: and I think you have to live it to know what we go through you really have to you have to be there you have to see it because nobody understands.

Anita Saltmarche: patients who come in are randomized I don’t select who goes into treatment and who gets a sham or control which means no treatment.

Speaker 2: actually I volunteered put anything to see if we can come up with something to solve this and I saw on the paper there was an opportunity so I went.

Speaker 1:  I knew this report right from day one because of my friend who had told me whatever you do get him in there get him to take the light therapy

Anita Saltmarche:  patients are treated for 12 weeks then we stopped treatment and they have a month with no treatment and then they come back and they reevaluate. essentially what we’re doing is evaluating the patients at three points,  baseline where are they before they start treatment, halfway through treatment at six weeks and that at completion of treatment at 12 weeks.

Speaker 1:  it was a complete change he became calm, he stopped wandering, he was able to sleep at night and he stopped searching for everything. And so a lot of the things stayed in the same place so it was very very oh it was miraculous to me. that happened just right after we started treatment and it was like wonderful little things like we noticed like it was like oh my god I can actually sleep at night so it was wonderful for me.

Anita Saltmarche: then we give them a month where we actually take away their product because some of them to continue to use them if we didn’t actually take it away.

Speaker 1: I nodded and I thought to myself I’m going to do it anyways and then she talked us I’m not going without this and then she told me that I had to give it up. so what started happening my husband started to wander right away right after he stopped he started to wander he started picking garbage up from the side of the road. I had to go and pick him up. It was awful he started immediately he forgot things so where I solved this accomplishment it was like oh my god I’m right back to to help. and it started like almost like a week later.

Anita Saltmarche: they have a month with no treatment and then they come back and they’re tested again using standardized tools that are all accepted and used in a clinical research community. and then after that, we teach them how to use the equipment and they take it home and they’ll continue.

Narrator:  pilot study is a good first step in validating the efficacy of photobiomodulation for Alzheimer’s disease especially that it is blinded in placebo control we are now planning to raise the level of evidence by doing bigger trials.

Lew Lim: hope you are taking away a better understanding of photobiomodulation and we did a greater appreciation of his potential. We’re looking forward to using light to brighten your life.


Speakers with their credentials.

Dr. Lew Lim is an engineer and a Doctor of Natural Medicine with additional diplomas in Medical Neuroscience and Business and Accountancy. He obtained his degrees and diplomas from the University of California at Berkeley, University of Sheffield, Duke University, Quantum University and The Chartered Institute of Management Accountants, UK.


Anita Saltmarche completed her Masters of Health Sciences from McMaster University, Hamilton, ON, Canada. She was a geriatric clinical nurse specialist for over a decade at Sunnybrook Health Science in Toronto as well as other leadership positions across the healthcare system. Anita maintains a clinical practice and provides research and other consulting services to a broad group of clients ranging from the Ontario Ministry of Health & Long Term Care to a number of private sector companies and non-profit health organizations. As principal and co-investigator on peer-reviewed research projects, she has published numerous papers in well-respected journals.



Massachusetts General Hospital


Associate Professor, Dermatology, Harvard Medical School

Associate Chemist, Dermatology, Massachusetts General Hospital